The Kynix Blog

Washington State University physicists have found a way to write an electrical circuit into a crystal, opening up the possibility of transparent, three-dimensional electronics that, like an Etch A Sketch, can be erased and reconfigured. The work, to appear in the on-line journal Scientific Reports, serves as a proof of concept for a phenomenon that WSU researchers first discovered by accident four years ago. At the time, a doctoral student found a 400-fold increase in the electrical conductivity of a crystal simply by leaving it exposed to light. Matt McCluskey, a WSU professor of physics and materials science, has now used a laser to etch a line in the crystal. With electrical contacts at each end of the line, it carried a current. "It opens up a new type of electronics where you can define a circuit optically and then erase it and define a new one," said McCluskey. "It's exciting that it's reconfigurable. It's also transparent. There are certain applications where it would be neat to have a circuit that is on a window or something like that, where it actually is invisible electronics." Ordinarily, a crystal does not conduct electricity. But when the crystal strontium titanate is heated under the right conductions, it is altered so light will make it conductive. The phenomenon, called "persistent photoconductivity," also occurs at room temperature, an improvement over materials that require cooling with liquid nitrogen. "We're still trying to figure out exactly what happens," said McCluskey. He surmises that heat forces strontium atoms to leave the material, creating light-sensitive defects responsible for the persistent photoconductivity. McCluskey's recent work increased the crystal's conductivity 1,000-fold. The phenomenon can last up to a year. "We look at samples that we exposed to light a year ago and they're still conducting," said McCluskey. "It may not retain 100 percent of its conductivity, but it's pretty big." Moreover, the circuit can be by erased by heating it on a hot plate and recast with an optical pen. "It's an Etch A Sketch," said McCluskey. "We've done it a few cycles. Another engineering challenge would be to do that thousands of times." The research was funded by the National Science Foundation. Co-authors on the paper are former students Violet Poole and Slade Jokela. The work is in keeping with WSU's Grand Challenges, a suite of initiatives aimed at addressing large societal problems. It is particularly relevant to the challenge of Smart Systems and its theme of foundational and emergent materials. Ref.KY163-NX1255GBKY163-TSX-3225

A bump circuit with flexible tuning ability that uses 500 times less power and is smaller than previous circuits has been demonstrated by researchers at the University of Tennessee in the US."The challenges and requirements of the analogue deep-learning system inspired us to come up with this radically new design," said Junjie Lu, the lead author. "We implemented the bump circuit by preceding the current correlator with a novel nano-power tunable transconductor to achieve variable width and height. By significantly reducing the power consumption of the bump circuit, this work makes possible the realisation of analogue learning and signal processing systems that achieve better energy efficiency than their digital equivalents, and ultimately fully autonomous systems, which are able to get both information and energy from the environment without external intervention."Towards flexible transferThe bump circuit is a family of circuits with bell-shaped, non-linear transfer functions. First appearing in 1991, they are widely used to provide similarity or distance measures in analogue signal processing systems such as support vector machines, neural networks and analogue machine-learning systems.The original bump circuit design lacked the ability to change the width of its transfer function, which is desirable in many applications to represent distributions with different variance or templates with different model parameters. A common approach to solve this is to pre-scale the input voltage, but the circuits required are physically large and consume a lot of power. Other approaches also have limitations such as complex circuitry, large physical size, and a restricted number of possible widths achievable.Hidden depthsThe researchers from the University of Tennessee designed their circuit as an important building block in an analogue deep-learning machine, which is able to perform unsupervised learning and extract salient features from high-dimensional input data, with a much better power efficiency than the existing digital machine learning implementations.Large-scale systems require the computational element, or bump circuit in this case, to be very efficient in both power and area. It is also important that the output features, which are the confidence scores that the current input belongs to each of the previous observations, take both the mean distances and probabilistic variances into account. A bump circuit that has a tunable centre for mean tuning, width for variance tuning, and height for normalisation is therefore highly desirable, and if these three bump parameters can be individually tuned and controlled by a single signal, this would greatly help with on-chip trainability.To achieve the variable height and width, the researchers designed and incorporated a novel transconductor, linearised using the drain resistances of saturated transistors. They adopted a pseudo-differential structure to allow operation with a low supply voltage, and designed a common mode feedback circuit to provide common mode rejection for the pseudo-differential structure to get a tunable bump height.The whole circuit uses 18.9 nW power from 3 V supply which is 1/500 th of the power of the next best bump circuit with tunable width. Implemented in 0.13 µm CMOS, it is smaller in area by 6%, and has maximum flexibility through the individual tunability of the three key bump function parameters. Another feature is that multiple bump circuits can be easily cascaded to represent multivariate probability.A vision of the futureWith power scaling in CMOS tapering off, there has been renewed interest in analogue computation recently, and the researchers expect to see some very exciting results in this area. They are currently working to integrate low-power circuits, such as their bump circuit, into larger systems for real-world applications."One application area we've been working on is machine vision," said Lu. "We've been working with image processing and machine vision researchers to build a complete pipeline using analogue circuits. This circuit helps to provide a path to implementing multi-dimensional kernel methods for machine learning."Systems using the bump circuit could find application in many areas such as healthcare monitoring, environmental monitoring, process control and battlefield surveillance. In addition, the nano-power tunable linear transconductor developed in this work, which has the advantages of ultra-low power, large input range and gm tunability, could be used in a huge range of applications such as amplifiers, filters and oscillators.Related products:LMV1031UR-20LM4889MALM4867MTE

Inflammation is a good thing when it's fighting off infection, but too much can lead to autoimmune diseases or cancer. In efforts to dampen inflammation, scientists have long been interested in CC chemokine receptor 2 (CCR2)—a protein that sits on the surface of immune cells like an antenna, sensing and transmitting inflammatory signals that spur cell movement toward sites of inflammation. Researchers at the Skaggs School of Pharmacy and Pharmaceutical Sciences at University of California San Diego have now determined the 3D structure of CCR2 simultaneously bound to two inhibitors. Understanding how these molecules fit together may better enable pharmaceutical companies to develop anti-inflammatory drugs that bind and inhibit CCR2 in a similar manner.CCR2 and associated signaling molecules are known to play roles in a number of inflammatory and neurodegenerative diseases, including multiple sclerosis, asthma, diabetic nephropathy and cancer. Many drug companies have attempted to develop drugs that target CCR2, but none have yet made it to market."So far drugs that target CCR2 have consistently failed in clinical trials," said Tracy Handel, PhD, professor in the Skaggs School of Pharmacy. "One of the biggest challenges is that, to work therapeutically, CCR2 needs to be turned 'off' and stay off completely, all of the time. We can't afford ups and downs in its activity. To be effective, any small molecule drug that inhibits CCR2 would have to bind the receptor tightly and stay there. And that's difficult to do."Handel led the study with Irina Kufareva, PhD, project scientist at Skaggs School of Pharmacy, and Laura Heitman, PhD, of Leiden University. The study's first author is Yi Zheng, PhD, postdoctoral researcher also at Skaggs School of Pharmacy.CCR2 spans the membrane of immune cells. Part of the receptor sticks outside the cell and part sticks inside. Inflammatory molecules called chemokines bind the external part of CCR2 and the receptor carries that signal to the inside of the cell. Inside the cell, CCR2 changes shape and binds other communication molecules, such as G proteins, triggering a cascade of activity. As a result, the immune cells move, following chemokine trails that lead them to places in the body where help is needed.In this study, the researchers used a technique known as X-ray crystallography to determine the 3D structure of CCR2 with two molecules bound to it simultaneously—one at each end.That's a huge accomplishment because, Kufareva said, "Receptors that cross the cell membrane are notoriously hard to crystalize. To promote crystallization, we needed to alter the amino acid sequence of CCR2 to make the receptor molecules assemble in an orderly fashion. Otherwise, when taken out of the cell membrane, they tend to randomly clump together. "Handel, Kufareva and team also discovered that the two small molecules binding CCR2 turn the receptor "off" by different but mutually reinforcing mechanisms. One of the small molecules binds the outside face of the receptor and blocks binding of the natural chemokines that normally turn the receptor "on." The other small molecule binds the face of the receptor inside the cell, where the G protein normally binds, preventing inflammatory signal transmission. According to Handel, the latter binding site has never been seen before.   

Accelerometers play a crucial role in measuring motion and acceleration with precision. These sensors have become indispensable across industries due to their ability to capture detailed movement data. In aerospace, they ensure flight stability and navigation, while in the automotive sector, they enhance safety by supporting vehicle stability systems. The industrial sector relies on accelerometers for predictive maintenance, reducing costs and improving efficiency. Their evolution has also fueled innovations in consumer electronics, enabling realistic motion control in gaming and accurate navigation in smartphones. This rich accelerometer history highlights how advancements in this technology continue to transform modern life.Early Developments in Accelerometer History (1940s–1960s)The First Commercial AccelerometersThe 1940s marked a turning point in accelerometer history with the introduction of the first commercial accelerometer. In 1943, Brüel & Kj?r (B&K) produced the Type 4301, the first piezoelectric accelerometer. This device utilized Rochelle salt crystals, offering a sensitivity of 35–50 mV/g and a resonant frequency of 2–3 kHz. It set the foundation for future advancements in accelerometer technology. By the 1950s, manufacturers transitioned to ceramic elements, which doubled sensitivity and increased resonance to 5 kHz. These developments improved the performance and reliability of accelerometers, making them more suitable for industrial and scientific applications.The commercial accelerometer industry continued to evolve throughout the 1960s. In 1963, Kistler introduced the first two-wire piezoelectric accelerometer, which showcased advancements in design and functionality. By 1964, compression-type accelerometers emerged, reducing susceptibility to case loading and base strain. These innovations highlighted the rapid progress in accelerometer development during this era.YearDevelopmentKey Features1943Type 4301First commercial piezoelectric accelerometer, sensitivity of 35–50 mV/g1950sTransition to ceramic elementsDoubled sensitivity, increased resonance to 5 kHz1963First two-wire piezoelectric accelerometerImproved design and functionality1964Compression-type accelerometersReduced susceptibility to case loading and base strainMaterial Advancements and Early DesignsMaterial advancements played a crucial role in the evolution of accelerometers during the mid-20th century. Early accelerometers were bulky and expensive, limiting their applications. The introduction of piezoelectric technology marked a significant leap forward. Piezoelectric accelerometers, which relied on materials like Rochelle salt and ceramics, offered higher sensitivity and better performance. These materials allowed engineers to design compact and economically viable sensors, broadening their use across industries.The development of strain gage accelerometers in the early 1940s further enhanced measurement capabilities. Strain gages, invented independently by A. Ruge and E. Simmons in 1938, became a cornerstone of accelerometer technology. By the 1960s, advancements in piezoresistive accelerometers improved accuracy and durability, paving the way for more sophisticated designs.The transition from bulky devices to compact sensors illustrated significant material advancements.Piezoelectric technology enhanced the functionality of accelerometers.Strain gage accelerometers improved measurement capabilities in various fields.Applications in Aerospace and Military TechnologyThe aerospace and military sectors were among the earliest adopters of accelerometer technology. During World War II, accelerometers played a vital role in aircraft navigation and missile guidance systems. The first commercial accelerometers, such as the Type 4301, were used to measure vibration and acceleration in aircraft. These devices ensured stability and performance under extreme conditions.In the 1950s and 1960s, accelerometers became integral to space exploration. NASA utilized piezoelectric accelerometers to monitor vibrations in spacecraft and rockets. These sensors provided critical data for ensuring the safety and success of missions. Military applications also expanded during this period, with accelerometers being used in guided missiles and advanced weaponry.The evolution of accelerometer technology during this era demonstrated its growing importance in high-stakes environments. The ability to measure motion and acceleration with precision revolutionized aerospace and military operations.Mid-Century Breakthroughs in Accelerometers (1970s–1990s)Miniaturization and the Rise of MEMS TechnologyThe 1970s marked a pivotal moment in accelerometer history with the emergence of microelectromechanical systems (MEMS) technology. Engineers began exploring ways to miniaturize accelerometers, making them more compact and cost-effective. MEMS accelerometers, built using silicon-based materials, revolutionized the industry by enabling the production of smaller, lighter, and more affordable sensors. This development allowed accelerometers to transition from specialized industrial tools to devices suitable for broader applications.MEMS technology also improved the performance of accelerometers. These sensors offered higher sensitivity and better accuracy, making them ideal for precise measurement tasks. By the 1980s, MEMS accelerometers had become a cornerstone of accelerometer evolution, paving the way for their integration into consumer electronics and other emerging fields.Improved Calibration and SensitivityAdvancements in calibration techniques during this period significantly enhanced the accuracy of accelerometer measurements. Engineers developed methods to reduce errors caused by temperature fluctuations and mechanical stress. These improvements ensured that accelerometers could deliver consistent and reliable data across various environments.The sensitivity of accelerometers also saw remarkable progress. Innovations in piezoresistive and piezoelectric materials allowed for the detection of even the smallest vibrations and accelerations. This heightened sensitivity expanded the range of accelerometer applications, particularly in fields requiring precise motion analysis, such as robotics and medical devices.Expansion into Automotive and Industrial ApplicationsThe 1970s and 1980s witnessed a surge in the use of accelerometers in automotive and industrial sectors. In the automotive industry, accelerometers became essential for airbag deployment systems, anti-lock braking systems (ABS), and vehicle stability control. These applications improved passenger safety and vehicle performance.In industrial settings, accelerometers played a crucial role in monitoring machine vibrations and predicting equipment failures. The development of piezoelectric accelerometers during World War II had already laid the groundwork for this application. By the 1950s, mass production of vibration detection instruments indicated a growing demand for accelerometers in industrial environments. This trend continued into the 1980s, as industries increasingly relied on accelerometers for predictive maintenance and operational efficiency.The evolution of accelerometer technology during this era demonstrated its versatility and growing importance across multiple industries. From miniaturization to improved sensitivity, these advancements shaped the modern accelerometer landscape.Modern Innovations in Accelerometer Technology (2000s–2020s)Image Source: pexelsTriaxial Accelerometers and Integrated SystemsThe 2000s saw a significant leap in accelerometer development with the widespread adoption of triaxial accelerometers. These sensors measure acceleration along three axes—X, Y, and Z—providing a comprehensive understanding of motion. This capability has proven invaluable in applications requiring precise motion tracking, such as inertial navigation systems (INS). INS often integrate triaxial accelerometers with gyroscopes to measure angular velocity and linear acceleration. This combination is essential in aerospace and automotive sectors, where accurate navigation and stability are critical.Triaxial accelerometers have also transformed vibration analysis, a key technique in condition-based maintenance (CBM) systems. These sensors monitor vibration patterns in rotating equipment, enabling early detection of issues like imbalance and bearing wear. By capturing data in multiple dimensions, triaxial accelerometers enhance the effectiveness of failure mode identification, reducing downtime and maintenance costs.Key Benefits of Triaxial Accelerometers:Comprehensive motion tracking across three axes.Enhanced vibration analysis for predictive maintenance.Improved integration with other systems, such as gyroscopes, for advanced applications.The evolution of triaxial accelerometers highlights their growing importance in modern technology. Their ability to provide detailed motion data has expanded their use across industries, from aerospace to industrial machinery.Advancements in Durability and Temperature ResistanceModern accelerometers have become more robust, thanks to advancements in materials and design. Engineers have developed sensors capable of withstanding extreme conditions, including high temperatures, intense vibrations, and corrosive environments. These improvements have expanded the range of accelerometer applications, particularly in industries like oil and gas, where equipment operates under harsh conditions.Temperature resistance has been a critical focus in accelerometer development. High-performance accelerometers now maintain accuracy across a wide temperature range, ensuring reliable data collection in environments with fluctuating conditions. For example, accelerometers used in aerospace applications must function accurately at both high altitudes and ground level, where temperatures can vary significantly.Durability has also improved through the use of advanced materials like silicon carbide and specialized coatings. These innovations protect accelerometers from physical damage and chemical exposure, extending their lifespan and reducing maintenance requirements.Notable Advancements:Enhanced temperature resistance for reliable performance in extreme environments.Use of durable materials to protect against physical and chemical damage.Increased lifespan and reduced maintenance needs.These advancements demonstrate the ongoing evolution of accelerometer technology, ensuring that sensors remain reliable and effective in even the most challenging conditions.Applications in Wearable Technology and IoTThe rise of wearable technology and the Internet of Things (IoT) has created new opportunities for accelerometer applications. These sensors play a crucial role in devices designed to monitor health, improve safety, and enhance convenience. MEMS accelerometers, in particular, have become a cornerstone of wearable and IoT devices due to their small size, low power consumption, and high sensitivity.Wearable devices use accelerometers for various purposes, including health monitoring and activity tracking. For instance, smart inhalers track usage frequency and technique, helping patients adhere to medication schedules. Accelerometers also assist in stroke recovery by monitoring movement patterns, enabling personalized therapy plans. In smart wheelchairs, they track wheel rotation speed to assess mobility and prevent complications.IoT applications further highlight the versatility of accelerometers. Fall detection systems in wearable devices alert caregivers when a fall occurs, enhancing safety for at-risk individuals. Sleep monitoring devices analyze movement during sleep, aiding in the diagnosis of sleep disorders. These applications showcase how accelerometers contribute to improving quality of life.Key Applications in Wearable Technology and IoT:Health monitoring, including stroke recovery and medication adherence.Safety features like fall detection and mobility assessment.Lifestyle enhancements, such as sleep monitoring and activity tracking.The integration of accelerometers into wearable technology and IoT devices underscores their transformative impact on daily life. As these technologies continue to evolve, accelerometers will remain a vital component in shaping the future of connected devices.The Role of AI and Machine Learning in Accelerometer DataArtificial intelligence (AI) and machine learning have revolutionized the way accelerometer data is analyzed and interpreted. These technologies enable the extraction of meaningful insights from vast amounts of raw data, enhancing the functionality of accelerometers across various fields. By identifying patterns and trends, AI-driven models improve the accuracy and efficiency of motion analysis.Machine learning algorithms, such as Random Forest and Expectation Maximisation, have been applied to accelerometer data for tasks like behavioral classification and energy expenditure estimation. For example, researchers have used these methods to study wildlife behavior. They analyzed accelerometer readings to classify activities and estimate energy use. However, the study revealed challenges like overfitting and interpretability issues in machine learning models. It also highlighted how different classification methods could produce varying results, emphasizing the importance of careful model selection.AI has also improved accelerometer applications in healthcare. Machine learning models analyze accelerometer data from wearable devices to monitor physical activity, detect falls, and assess sleep patterns. These insights help healthcare providers develop personalized treatment plans and improve patient outcomes. In industrial settings, AI-powered accelerometers predict equipment failures by analyzing vibration patterns, reducing downtime and maintenance costs.Despite its benefits, the integration of AI with accelerometers presents challenges. Ensuring data quality is critical for accurate analysis. Poor-quality data can lead to unreliable predictions and misinterpretations. Additionally, the complexity of machine learning models can make them difficult to understand and apply effectively. Addressing these challenges requires robust data preprocessing techniques and transparent model designs.The combination of AI and accelerometer technology continues to shape industries and improve lives. From wildlife research to healthcare and industrial maintenance, these advancements demonstrate the transformative potential of accelerometers when paired with intelligent algorithms.The history of accelerometer technology showcases remarkable milestones that have shaped its evolution. Early innovations, such as piezoelectric sensors, laid the groundwork for modern advancements. Calibration techniques and sensor placement have significantly influenced data accuracy, as seen in studies involving humans and animals. Fabrication processes have also played a critical role in improving performance.Accelerometers have transformed industries by enabling groundbreaking applications. The automotive sector relies on them for safety systems like collision detection, while consumer electronics benefit from their integration into smartphones and wearables. The global accelerometer market, valued at $3.35 billion in 2023, is projected to reach $6.5 billion by 2032, driven by demand in industrial automation and energy-efficient solutions.Future advancements hold immense potential. Accelerometers will continue to enhance healthcare, industrial monitoring, and everyday technology. Their ability to adapt and evolve ensures they remain a cornerstone of innovation across multiple sectors.The journey of accelerometer technology reflects its profound impact on industries and daily life, with a promising future of continued growth and innovation.FAQWhat is the primary function of an accelerometer?An accelerometer measures acceleration forces acting on an object. These forces can be static, like gravity, or dynamic, caused by motion. By detecting changes in velocity, accelerometers help monitor movement, vibration, and orientation in various applications.How do MEMS accelerometers differ from traditional accelerometers?MEMS accelerometers are smaller, lighter, and more cost-effective than traditional accelerometers. They use microelectromechanical systems technology, which integrates mechanical and electronic components on a silicon chip. This innovation enables their use in compact devices like smartphones and wearables.Why are triaxial accelerometers important?Triaxial accelerometers measure acceleration along three axes: X, Y, and Z. This capability provides a complete picture of motion, making them essential for applications like navigation, vibration analysis, and wearable technology.How do accelerometers contribute to wearable technology?Accelerometers in wearables track movement, monitor physical activity, and detect falls. They also assist in health monitoring, such as analyzing sleep patterns or aiding stroke recovery. Their small size and low power consumption make them ideal for these devices.What challenges arise when using AI with accelerometer data?AI models analyzing accelerometer data face challenges like poor data quality and overfitting. These issues can lead to inaccurate predictions. Ensuring robust preprocessing and selecting appropriate machine learning models help address these challenges effectively.

Using state-of-the-art theoretical methods, UCSB researchers have identified a specific type of defect in the atomic structure of a light-emitting diode (LED) that results in less efficient performance. The characterization of these point defects could result in the fabrication of even more efficient, longer lasting LED lighting."Techniques are available to assess whether such defects are present in the LED materials and they can be used to improve the quality of the material," said materials professor Chris Van de Walle, whose research group carried out the work.In the world of high-efficiency solid-state lighting, not all LEDs are alike. As the technology is utilized in a more diverse array of applications—including search and rescue, water purification and safety illumination, in addition to their many residential, industrial and decorative uses—reliability and efficiency are top priorities. Performance, in turn, is heavily reliant on the quality of the semiconductor material at the atomic level."In an LED, electrons are injected from one side, holes from the other," explained Van de Walle. As they travel across the crystal lattice of the semiconductor—in this case gallium-nitride-based material—the meeting of electrons and holes (the absence of electrons) is what is responsible for the light that is emitted by the diode: As electron meets hole, it transitions to a lower state of energy, releasing a photon along the way.Occasionally, however, the charge carriers meet and do not emit light, resulting in the so-called Shockley-Read-Hall (SRH) recombination. According to the researchers, the charge carriers are captured at defects in the lattice where they combine, but without emitting light.The defects identified involve complexes of gallium vacancies with oxygen and hydrogen. "These defects had been previously observed in nitride semiconductors, but until now, their detrimental effects were not understood," explained lead author Cyrus Dreyer, who performed many of the calculations on the paper."It was the combination of the intuition that we have developed over many years of studying point defects with these new theoretical capabilities that enabled this breakthrough," said Van de Walle, who credits co-author Audrius Alkauskas with the development of a theoretical formalism necessary to calculate the rate at which defects capture electrons and holes.The method lends itself to future work identifying other defects and mechanisms by which SRH recombination occurs, said Van de Walle."These gallium vacancy complexes are surely not the only defects that are detrimental," he said. "Now that we have the methodology in place, we are actively investigating other potential defects to assess their impact on nonradiative recombination."Reference:KY59-LM324MMKY59- LM2710KY59- LM3080 

The latest RECOM wide input-voltage range DC/DC converters are now available from Dengrove Electronic Components. The 1” x 1” 20-Watt RPA20-AW and 30-Watt RPA30-AW, and 2” x 1” 60-Watt RPA60-AW, deliver high power density and rugged performance with 1.6kV safety isolation and built-in short-circuit, over-voltage, over-current and over-temperature protection.The units satisfy industrial safety specifications including UL and IEC/EN60950-1, and also comply with EN50155, the harmonised European standard for railway electronic equipment. With their nominal 24V input voltage, and maximum range of 9V to 36V, they can fulfil a wide range of applications on-board railway rolling stock or in industrial controls and general distributed power architectures.Output-voltage options are 3.3V, 5V, 12V, 15V, ±12V or ±15V for the RPA20-AW and RPA30-AW, and 12V, 15V or 24V for the RPA60-AW. The single-output versions can be trimmed by ±10%, by connecting an external resistor to the trim pin.All models operate with no minimum load, and maintain a tightly regulated output with low ripple and noise.The converters operate at high efficiency, up to 93.3% for the RPA60-AW, and provide options including an on/off control pin and a glued aluminium heatsink to extend the ambient operating-temperature range to 60°C at full power and over 80°C with derating.All units assure high reliability backed up by RECOM’s 3-year warranty.Reference:KY68-DS1200DKY68-SL1287KY68-SC486